1. Field of the Invention
This invention is directed to dirt extraction systems, in general, and, more paticularly to such systems which are used to extract dirt from continuous ductwork without the necessity of disassembling the ductwork or the like.
2. Prior Art.
There are many systems known in the art which are used for extracting dirt from various surfaces. In particular, there are many systems which are known for removing accumulated dirt and debris from tubes or channels.
Perhaps the simplest known device of this kind is a pipe cleaner which is caused to pass through the stem of a smoking pipe to clean sediment from the stem. Other types of cleaning instruments include knives, scrapers and the like which are used to remove grime from the interior of the bowl of a smoking pipe or any other device.
Another well known device of this type is the so called rotary router which is caused to pass through pipes, drains, culverts or other clogged plumbing. However, this device normally includes a cutting tool at the operating end thereof which is used to cut through blockages in the pipe without affecting the pipe itself.
Other types of devices which are capable of passing through pipes or conduits are referred to as "snakes". However, these devices are usually intended to be much smaller than the conduit through which they pass and are used to pull other items (e.g. wire) through the conduits or to clear the conduits in similar fashion to the rotary router noted above.
A rotary device which is known in the art and which is used for cleaning purposes is used in the field of boilers or the like. This device includes a tool which comprises of plurality of flexible, elongated metal cables which have enlarged bodies fixed to the ends thereof. This type of tool is used to clean the inside of boilers by causing the cables to rotate, thereby driving the spheroids at the ends thereof against the boiler to remove the rust and other undesired sediment from the interior of the boiler. However, this tool requires that the component being cleaned is of relatively heavy duty steel or the like which will not be damaged or destroyed by the impact of the cleaning tool.
While there are tools or apparatus of the type described above none of the units has been found acceptable for cleaning ductwork such as found in air conditioning systems or the like. More particularly, many air conditioning ducts include convolutions therein which inhibit the use of cleaning instruments of the type known.
The problems thus encountered with cleaning of such ductwork are significant. The problems can make the cleaning of equipment extremely expensive. For example, on a vessel such as an aircraft carrier, submarine or the like, all of the ductwork must be cleaned periodically because of the nature of the ventilation system operation. That is, the system is, typically, balanced by the configuration of the ductwork and the like. Howewever, when a build-up of dirt and debris occurs in one area, the ductwork and ventilation system becomes out of balance. Th residue situation is aggravated because the clogged portion of the system becomes hotter which is conducive to further build-up of sediment and the like.
In the past it has been necessary to tear down the ventilating ductwork in order to remove the dirt accumulation, and to clean the various segments by hand. This, of course, causes the ventilation system to be inoperative for lengthy periods of time wherein the area to be ventilated (building, ship or the like) is less useful than is desired.
Moreover, it is readily apparent that tearing down an entire ventilation system for the purpose of cleaning of the same and then reassembling the same ventilation system, becomes an inordinate headache as well as requiring considerable expense. It has been projected that the cost of rehabilitating the ventilating system on a single ship the size of an aircraft carrier is in the neighborhood of a quarter of a million dollars. Inasmuch as the cleaning operation is performed on an average of twice a year, the expense can become prohibitive.
Consequently, it is highly desirable to produce a method and apparatus for cleaning ventilation ductwork, or the like, in-situ so that down-time is reduced and the cost of cleaning is minimized. In addition, the method and apparatus must operate in a fashion to do a worthwhile cleaning job without causing damage to the ventilation system.